An electric conductor wire

ABSTRACT

An electric conductor wire of aluminum or aluminum alloy with a diameter less than 5 mm., is covered with a layer containing nickel with a thickness in the range of from 0.1 to 10 Mu . In order to improve the adhesiveness of the layer, the layer consists of an alloy of nickel and zinc with a proportion of zinc up to 75 percent.

United States Patent Hansson 1 Jan. 18, 1972 [54] AN ELECTRIC CONDUCTOR WIRE [72] Inventor: I-Ians Olof Hansson, Sollentuna, Sweden [73] Assignee: Telefonaktlebolaget LM Ericsson,

Stockholm, Sweden [22] Filed: Nov. 24, I969 [211 App]. No.: 879,567

[30] Foreign Application Priority Data Dec. 9, 1968 Sweden 16795/68 May 27, 1969 Sweden 7440/69 [52] U.S.CI ..l74/128, 29/19I.6, 29/197, 174/ 1 26 CP [5 l Int. Cl. ..H0lb 5/08 [58] Field ofSearch ..174/l26, 126.2,128, 94, 126 R,

[56] References Cited UNITED STATES PATENTS 2,233,410 4/1941 Frasch ..29/l91.6

2,427,727 9/1947 Huntley 1 74/94 3,254,970 6/1966 Dittrich ..29/ l 9 I .6 3,367,796 2/1968 Saums 17411262 UX FOREIGN PATENTS OR APPLICATIONS 217,784 10/1958 Australia l74/126.2

OTHER PUBLICATIONS Dummer et al. Wires and R. F. Cables 1968 Pitman London pp. 21 table 36 Primary Examiner-E. A. Goldberg Attorney-Hane & Baxley [5 7] ABSTRACT An electric conductor wire of aluminum or aluminum alloy with a diameter less than 5 mm., is covered with a layer containing nickel with a thickness in the range of from 0.1 to 10 11.. In order to improve the adhesiveness of the layer, the layer consists of an alloy of nickel and zinc with a proportion of zinc up to 75 percent.

7 Claims, 2 Drawing Figures PATENTEDJANIBWYZ 3,636,242

INVENTOR. HANS 0L 0F HANSSON A 1- TOENE rs ELECTRIC CONDUCTOR WIRE This invention relates to an electric wire conductor, mainly comprising aluminum, with a diameter less than 5 mm.

Owing to the rising price of copper the latter metal has been replaced by aluminum or aluminum alloy in electrical cables.

In order to clamp-connect conductors of aluminum, it demands special expensive measures dependent on the tendency of the latter metal to oxidize. The occurrence of contact resistance can be so large due to the oxide layer that temperatures entailing the risk of fire were observed in the clamp-connections.

The use of aluminum conductors according to the presentinvention is made possible by providing the conductor on the surface with a layer containing nickel with a thickness in the range of from 0.1 to

Improved adhesiveness or bonding of the layer on the conductor is obtained according to the invention when the applied layer consists of an alloy of nickel and zinc with a proportion of zinc in the range of from 25 percent to 75 percent. Good results are obtained when the alloy consists of zinc in the range of from 40 percent to 60 percent and it is particularly suitable to have an admixture of zinc in the range of from 45 percent to 55 percent. With nickel and zinc are here meant the respective metals of commercial grade, that is, impurities may be present to some extent.

The layer is applied by means of an electrochemical method known per se for example the fluoborate method.

The aluminum conductor in this manner provided with a layer according to the invention can be readily soldered with usual tin solder and resin fluxing material.

The manufacture may be started with a wire of substantially the desired final diameter, which is to be covered with a layer according to the invention, or the manufacture may be started with a thicker diameter, which is covered with a layer according to the invention and then is drawn to a desired thinner diameter.

The invention also includes twisted, multiwire cores where each single wire line is provided with a layer according to the invention. The layer hereby reduces the mutual resistance between the individual wires which is of great importance in order to obtain good contact at the connection of a wire at a connection point.

For wire armoring of electrical cables it can, for example for submarine cable, be suitable to use aluminum wires covered with a layer according to the invention. Such a wire armoring becomes light and resistant to corrosion.

A conductor with a layer according to the invention has qualities similar to those of a copper conductor and can be insulated with all usual insulating means, for example paper, plastics or oil.

in the accompanying drawing, several preferred embodiments of the invention are shown by way of illustration and not by way of limitation.

In the drawing:

FIG. 1 is a cross section of an electric wire conductor according to the invention; and

FIG. 2 is a cross section of a cable formed by wire conductors according to the invention.

Referring now to the figures more in detail, FIG. 1 shows an electric wire conductor 1 having a solid core wire 2 made of aluminum or an aluminum alloy and sheathed by a layer 3 of nickel or any of the alloys as set forth in the specification.

As also set forth in the specification, the maximal diameter of the core is less than 5 mm. and the thickness of the layer 3 is between 0.1 to lOu.

The cable of FIG. 2 is formed by twisting a plurality of wire conductors l as described in connection with FIG. 1. The wires are twisted so that they substantially contact each other. The aforedescribed surface layer 3 of the wire conductors reduces the resistance between the individual wires in contact with each other. As a result, high-quality connections between the cable and a connecting point such as a connector can be conveniently and safely made.

I claim: 1. An electric wire conductor consisting a one-piece core wire of aluminum or aluminum alloy having a diameter of less than 5 mm., and an outer layer containing nickel encompassing said core wire bonded thereto, said outer layer having a thickness of O. l to 10 microns.

2. The electric wire conductor according to claim 1 wherein 7 said outer layer consists of nickel except for impurities.

3. The electric wire conductor according to claim 1 wherein said outer layer consists of an alloy of nickel and zinc with at least 25 percent nickel and a balance of zinc except for impurities.

4. The electric wire conductor according to claim 1 wherein said outer layer consists of zinc in therange of 25 to percent, the balance being nickel except for impurities.

5. The electric wire conductor according to claim 4 wherein the zinc content of the outer layer is in the range of 40 to 60 percent.

6. The electric wire conductor according to claim 4 wherein the zinc content of the outer layer is in the range of 45 to 55 percent.

7. An electric cable comprising a plurality of twisted wire conductors, each of said wire conductors comprising a onepiece core wore of aluminum or aluminum alloy having a diameter of less than 5 mm., and an outer layer containing nickel encompassing said core wire bonded thereto, said outer layer having a thickness of 0.1 to 5 microns. 

2. The electric wire conductor according to claim 1 wherein said outer layer consists of nickel except for impurities.
 3. The electric wire conductor according to claim 1 wherein said outer layer consists of an alloy of nickel and zinc with at least 25 percent nickel and a balance of zinc except for impurities.
 4. The electric wire conductor according to claim 1 wherein said outer layer consists of zinc in the range of 25 to 75 percent, the balance being nickel except for impurities.
 5. The electric wire conductor according to claim 4 wherein the zinc content of the outer layer is in the range of 40 to 60 percent.
 6. The electric wire conductor according to claim 4 wherein the zinc content of the outer layer is in the range of 45 to 55 percent.
 7. An electric cable comprising a plurality of twisted wire conductors, each of said wire conductors comprising a one-piece core wore of aluminum or aluminum alloy having a diameter of less than 5 mm., and an outer layer containing nickel encompassing said core wire bonded thereto, said outer layer having a thickness of 0.1 to 5 microns. 